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      1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
      2 /*
      3  * Copyright (c) 1993, 1994, 1995, 1996, 1997
      4  *	The Regents of the University of California.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *	This product includes software developed by the Computer Systems
     17  *	Engineering Group at Lawrence Berkeley Laboratory.
     18  * 4. Neither the name of the University nor of the Laboratory may be used
     19  *    to endorse or promote products derived from this software without
     20  *    specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #ifndef _diag_control_h
     36 #define _diag_control_h
     37 
     38 #include "compiler-tests.h"
     39 
     40 #ifndef _MSC_VER
     41   /*
     42    * Clang and GCC both support this way of putting pragmas into #defines.
     43    * We don't use it unless we have a compiler that supports it; the
     44    * warning-suppressing pragmas differ between Clang and GCC, so we test
     45    * for both of those separately.
     46    */
     47   #define DIAG_DO_PRAGMA(x) _Pragma (#x)
     48 #endif
     49 
     50 /*
     51  * XL C 12.1 and 13.1 for AIX require no attention in this department.
     52  * XL C 16.1 defines both __GNUC__ and __clang__, so has to be tested first.
     53  */
     54 #if ND_IS_AT_LEAST_XL_C_VERSION(16,1)
     55   /*
     56    * See respective Clang note below.
     57    */
     58   #define DIAG_OFF_ASSIGN_ENUM \
     59     DIAG_DO_PRAGMA(clang diagnostic push) \
     60     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wassign-enum")
     61   #define DIAG_ON_ASSIGN_ENUM \
     62     DIAG_DO_PRAGMA(clang diagnostic pop)
     63 /*
     64  * The current clang compilers also define __GNUC__ and __GNUC_MINOR__
     65  * thus we need to test the clang case before the GCC one
     66  */
     67 #elif ND_IS_AT_LEAST_CLANG_VERSION(2,8)
     68   /*
     69    * Clang complains if you OR together multiple enum values of a
     70    * given enum type and them pass it as an argument of that enum
     71    * type.  Some libcap-ng routines use enums to define bit flags;
     72    * we want to squelch the warnings that produces.
     73    */
     74   #define DIAG_OFF_ASSIGN_ENUM \
     75     DIAG_DO_PRAGMA(clang diagnostic push) \
     76     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wassign-enum")
     77   #define DIAG_ON_ASSIGN_ENUM \
     78     DIAG_DO_PRAGMA(clang diagnostic pop)
     79 
     80   /*
     81    * It also legitimately complains about some code in the BSD
     82    * getopt_long() - that code explicitly and deliberately
     83    * violates the contract by permuting the argument vector
     84    * (declared as char const *argv[], meaning "I won't change
     85    * the vector by changing any of its elements), as do the
     86    * GNU and Solaris getopt_long().  This is documented in the
     87    * man pages for all versions; it can be suppressed by setting
     88    * the environment variable POSIXLY_CORRECT or by putting a "+"
     89    * at the beginning of the option string.
     90    *
     91    * We suppress the warning.
     92    */
     93   #define DIAG_OFF_CAST_QUAL \
     94     DIAG_DO_PRAGMA(clang diagnostic push) \
     95     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wcast-qual")
     96   #define DIAG_ON_CAST_QUAL \
     97     DIAG_DO_PRAGMA(clang diagnostic pop)
     98 
     99   /*
    100    * Suppress deprecation warnings.
    101    */
    102   #define DIAG_OFF_DEPRECATION \
    103     DIAG_DO_PRAGMA(clang diagnostic push) \
    104     DIAG_DO_PRAGMA(clang diagnostic ignored "-Wdeprecated-declarations")
    105   #define DIAG_ON_DEPRECATION \
    106     DIAG_DO_PRAGMA(clang diagnostic pop)
    107 
    108   /*
    109    * Clang supports the generic C11 extension even if run with the -std=gnu99
    110    * flag, which leads FreeBSD <sys/cdefs.h> to use the extension, which
    111    * results in Clang emitting a -Wc11-extensions warning. The warning is not
    112    * documented in the user manual, but it happens with Clang 10.0.1 on
    113    * FreeBSD 12.2, so let's use that as a reference.
    114    */
    115   #if ND_IS_AT_LEAST_CLANG_VERSION(10,0)
    116     #define DIAG_OFF_C11_EXTENSIONS \
    117       DIAG_DO_PRAGMA(clang diagnostic push) \
    118       DIAG_DO_PRAGMA(clang diagnostic ignored "-Wc11-extensions")
    119     #define DIAG_ON_C11_EXTENSIONS \
    120       DIAG_DO_PRAGMA(clang diagnostic pop)
    121   #endif
    122 
    123   /*
    124    * When Clang correctly detects an old-style function prototype after
    125    * preprocessing, the warning can be irrelevant to this source tree because
    126    * the prototype comes from a system header macro.
    127    */
    128   #if ND_IS_AT_LEAST_CLANG_VERSION(5,0)
    129     #define DIAG_OFF_STRICT_PROTOTYPES \
    130       DIAG_DO_PRAGMA(clang diagnostic push) \
    131       DIAG_DO_PRAGMA(clang diagnostic ignored "-Wstrict-prototypes")
    132     #define DIAG_ON_STRICT_PROTOTYPES \
    133       DIAG_DO_PRAGMA(clang diagnostic pop)
    134   #endif
    135 #elif ND_IS_AT_LEAST_GNUC_VERSION(4,6)
    136   /* GCC apparently doesn't complain about ORing enums together. */
    137 
    138   /*
    139    * It does, however, complain about casting away constness in
    140    * missing/getopt_long.c.
    141    */
    142   #define DIAG_OFF_CAST_QUAL \
    143     DIAG_DO_PRAGMA(GCC diagnostic push) \
    144     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wcast-qual")
    145   #define DIAG_ON_CAST_QUAL \
    146     DIAG_DO_PRAGMA(GCC diagnostic pop)
    147 
    148   /*
    149    * GCC warns about unused return values if a function is marked as
    150    * "warn about ignoring this function's return value".
    151    *
    152    * Clang appears to let you ignore a result without a warning by
    153    * casting the function result to void, so we don't appear to
    154    * need this for Clang.
    155    */
    156   #define DIAG_OFF_WARN_UNUSED_RESULT \
    157     DIAG_DO_PRAGMA(GCC diagnostic push) \
    158     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wunused-result")
    159   #define DIAG_ON_WARN_UNUSED_RESULT \
    160     DIAG_DO_PRAGMA(GCC diagnostic pop)
    161 
    162   /*
    163    * Suppress deprecation warnings.
    164    */
    165   #define DIAG_OFF_DEPRECATION \
    166     DIAG_DO_PRAGMA(GCC diagnostic push) \
    167     DIAG_DO_PRAGMA(GCC diagnostic ignored "-Wdeprecated-declarations")
    168   #define DIAG_ON_DEPRECATION \
    169     DIAG_DO_PRAGMA(GCC diagnostic pop)
    170   /*
    171    * GCC supports -Wc99-c11-compat since version 5.1.0, but the warning does
    172    * not trigger for now, so let's just leave it be.
    173    *
    174    * GCC does not currently generate any -Wstrict-prototypes warnings that
    175    * would need silencing as is done for Clang above.
    176    */
    177 #endif
    178 
    179 /*
    180  * GCC needs this on AIX for longjmp().
    181  */
    182 #if ND_IS_AT_LEAST_GNUC_VERSION(5,1)
    183   /*
    184    * Beware that the effect of this builtin is more than just squelching the
    185    * warning! GCC trusts it enough for the process to segfault if the control
    186    * flow reaches the builtin (an infinite empty loop in the same context would
    187    * squelch the warning and ruin the process too, albeit in a different way).
    188    * So please remember to use this very carefully.
    189    */
    190   #define ND_UNREACHABLE __builtin_unreachable();
    191 #endif
    192 
    193 #ifndef DIAG_OFF_ASSIGN_ENUM
    194 #define DIAG_OFF_ASSIGN_ENUM
    195 #endif
    196 #ifndef DIAG_ON_ASSIGN_ENUM
    197 #define DIAG_ON_ASSIGN_ENUM
    198 #endif
    199 #ifndef DIAG_OFF_CAST_QUAL
    200 #define DIAG_OFF_CAST_QUAL
    201 #endif
    202 #ifndef DIAG_ON_CAST_QUAL
    203 #define DIAG_ON_CAST_QUAL
    204 #endif
    205 #ifndef DIAG_OFF_WARN_UNUSED_RESULT
    206 #define DIAG_OFF_WARN_UNUSED_RESULT
    207 #endif
    208 #ifndef DIAG_ON_WARN_UNUSED_RESULT
    209 #define DIAG_ON_WARN_UNUSED_RESULT
    210 #endif
    211 #ifndef DIAG_OFF_DEPRECATION
    212 #define DIAG_OFF_DEPRECATION
    213 #endif
    214 #ifndef DIAG_ON_DEPRECATION
    215 #define DIAG_ON_DEPRECATION
    216 #endif
    217 #ifndef DIAG_OFF_C11_EXTENSIONS
    218 #define DIAG_OFF_C11_EXTENSIONS
    219 #endif
    220 #ifndef DIAG_ON_C11_EXTENSIONS
    221 #define DIAG_ON_C11_EXTENSIONS
    222 #endif
    223 #ifndef DIAG_OFF_STRICT_PROTOTYPES
    224 #define DIAG_OFF_STRICT_PROTOTYPES
    225 #endif
    226 #ifndef DIAG_ON_STRICT_PROTOTYPES
    227 #define DIAG_ON_STRICT_PROTOTYPES
    228 #endif
    229 #ifndef ND_UNREACHABLE
    230 #define ND_UNREACHABLE
    231 #endif
    232 
    233 #endif /* _diag_control_h */
    234